OMAPDSS: DISPC: Don't allow predecimation for writeback
OMAPDSS: DISPC: Don't allow predecimation for writeback

Since writeback writes to a buffer instead of reading from one, predecimation
doesn't make sense for it. Configure the width and height predecimation limits
to 1 if the plane is writeback.

Signed-off-by: Archit Taneja <49f60fff7e48ce8acf4d32f930e8060f85030a2d@ti.com>
Signed-off-by: Tomi Valkeinen <e1ca4dbb8be1acaf20734fecd2da10ed1d46a9bb@ti.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs